Colorimetric Detection of Mercuric Ion (Hg 2+ ) in Aqueous Media using DNA‐Functionalized Gold Nanoparticles

Color is everything: Hg2+ in aqueous media is detected by the formation of thymidine–Hg2+–thymidine coordination complexes, which raises the melting temperature of the DNA-hybridized gold nanoparticle probes and thus the temperature at which the probes disperse and effect a purple-to-red color change. The method has very high sensitivity and selectivity, and it provides a simple and fast colorimetric readout (see picture). Mercury is a widespread pollutant with distinct toxicological profiles, and it exists in a variety of different forms (metallic, ionic, and as part of organic and inorganic salts and complexes). Solvated mercuric ion (Hg2+), one of the most stable inorganic forms of mercury,1 is a caustic…

• NS
  National Science Foundation
• NI
  National Institutes of Health
• AF
  Air Force Office of Scientific Research
• AR
  Army Research Office